Linkage device of internal combustion engine

ABSTRACT

A linkage device of a V-type internal combustion engine rotates a pair of drive shafts for changing openings of swirl control valves. The linkage device receives reciprocating motion from an actuator through a rod. A center lever connected to the rod changes the reciprocating motion to swing motion and transfers the swing motion to right and left links. The right and left links are connected to the drive shaft through right and left levers, respectively. The right and left links and the right and left levers change the swing motion to rotational motion and apply the rotational motion to the drive shafts.

The contents of Application No. JP9-135036, with filing date May 26,1997 in Japan, are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a linkage device of an internalcombustion engine, and more particularly to a linkage device throughwhich a pair of drive shafts for operating swirl control valves in aV-type engine are rotated by reciprocating-motion generated by anactuator.

Japanese Patent Provisional Publication No. 6-173695 discloses an intakesystem for an in-line four-cylinder internal combustion engine whichdevice is provided with swirl control valves for controlling in-cylinderair flow such as swirl and tumble of air. These swirl control valves areconnected to a common drive shaft which is directly rotated by anactuator. An engine control unit outputs a drive signal determined by anengine operating condition such as load, engine rotation speed andengine temperature to the actuator in order to control the opening ofthe swirl control valves. If such an intake system is employed in aV-type engine, it is necessary to prepare two drive shafts forrespectively operating swirl control valves of two banks of the V-typeengine. In order to operate the two drive shafts, it is necessary toprovide two actuator or to provide one actuator for directly operatingone drive shaft and a linkage device for operating the other drive shaftutilizing the drive power of the actuator.

However, in such arrangements, the actuator is protrudedly installed atend portions of the drive shafts. Such an engine system with thisconventional device requires large space, and therefore the total lengthor height of the engine system may become large. Further, in case thatthe drive shafts are directly driven by the respective actuators, eachof the drive shafts is fixedly connected to each actuator so as not togenerate play therebetween. Therefore, if a temperature differenceoccurs in the engine in the longitudinal direction, the drive shaft maybe twisted and therefore the openings of the swirl control valves becomedifferent. This opening difference causes the dispersion of the swirlsamong the combustion chambers of the engine and the degradation of thecombustion. Consequently, the performance of the engine may be degraded.Further, in case that one of the two drive shafts is directly driven bythe actuator and the other drive shaft is driven by the actuator througha linkage device, it is difficult to synchronize the rotations of thetwo drive shafts. That is, the operation of the other drive shaft driventhrough the linkage device is delayed by play caused by the linkagedevice as compared with the drive shaft directly driven by the actuator.Therefore, the opening of the swirl control valves for one bank becomesdifferent from that of the swirl control valves for the other bank. Thisdispersion among the openings of the valves causes the dispersion amongthe swirls in the combustion chambers of the engine and the degradationof the combustion.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a linkage devicewhich enables two rotation shafts to be rotated by one drive sourcewhile improving in structure and size.

Another object of the present invention is to provide an improvedlinkage device which functions to suppress dispersion of openings ofswirl control valves if employed in an internal combustion engine.

A linkage device according to the present invention is for an internalcombustion engine and comprises a reciprocating member and a connectingmember comprising first and second supporting portions. The firstsupporting portion of the connecting member is rotatably connected tothe reciprocating member. A supporting member is rotatably supportingthe connecting member so that the first and second supporting portionsare swingable around the supporting member. First and second extendingmembers are rotatably connected to the second supporting portion of theconnecting member. The second extending member extends from the secondsupporting portion toward an opposite direction of an extendingdirection of the first extending member. First and second lever membersare rotatably connected to the first and second extending members,respectively. First and second rotation shafts are fixed to the firstand second lever members, respectively. The first and second rotationshafts are synchronously rotated when the reciprocating rod isreciprocated.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference numerals designate like parts andelements throughout all figures, in which:

FIG. 1 is a rear view of a V-type internal combustion engine employing alinkage device of the first embodiment according to the presentinvention;

FIG. 2 is a developed view of the linkage device and intake passages ofthe engine;

FIG. 3A is a partial top view of the linkage device of the firstembodiment according to the present invention;

FIG. 3B is a side view of the linkage device of FIG. 3A;

FIGS. 4A to 4C are side views which show different opening conditions ofswirl control valves operated by the linkage device;

FIG. 5 is a side view of the linkage device put in a full close state;

FIG. 6 is a side view which shows a main flow of intake air in intakepassages according to the openings of the swirl control valves;

FIG. 7 is a side view which shows a second embodiment of the linkagedevice according to the present invention; and

FIGS. 8A to 8C are side views which show different opening conditions ofswirl control valves operated by the linkage device of the secondembodiment.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 to 6, there is shown a first embodiment of alinkage device 20 installed in a V-type six-cylinder internal combustionengine 100 in accordance with the present invention.

As shown in FIG. 1, the linkage device 20 according to the presentinvention is installed in an intake system 1 including an intakecollector 2. The intake collector 2 has an inlet installation portion 2Aconnected to a throttle chamber (not shown). An outlet of the intakecollector 2 is connected to right intake passages 3A to 3F and leftintake passages 3G to 3L. The right intake passages 3A to 3F and theleft intake passages 3G to 3L are connected to a right bank 100R and aleft bank 100L of the engine 100, respectively.

As shown in FIG. 2, six pairs of the intake passages 3A and 3B, 3C and3D, 3E and 3F, 3G and 3H, 3I and 3J, and 3K and 3L are connected to sixcylinders #1, #2, #3, #4, #5 and #6 of the engine 100, respectively.Right swirl control valves 4A, 4B and 4C of a butterfly valve type areinstalled in the right intake passages 3B, 3D and 3F, respectively.Similarly, left swirl control valves 4D, 4E and 4F of a butterfly valvetype are installed in one of each pair of the left intake passages 3G,3I and 3K, respectively. The right swirl control valves 4A, 4B and 4Care fixedly connected to a right drive shaft 5A by means of screws.Similarly, the left swirl control valves 4D, 4E and 4F are fixedlyconnected to a left drive shaft 5B by means of screws.

As shown in FIGS. 3A and 3B, an actuator 6 of a vacuum-pressure controltype is connected to a rod 7 which reciprocates according to the changeof the vacuum pressure applied to the actuator 6. The rod 7 is rotatablyconnected to a center lever 8 by inserting a first supporting portion 8Aof a center lever 8 to a connecting hole 7A of the rod 7. A fulcrumportion (fulcrum hole) 8B of the center lever 8 is rotatably supportedto a center shaft 100A projecting from an engine body (part of an intakesystem) 100B. A second supporting portion 8C of the center lever 8 isrotatably connected to a right link 9 and a left link 11. The centerlever 8 is a so-called bell crank which pivots on the center shaft 100Aso that the first and second supporting portions 8A and 8C swing aroundthe center shaft 100A inserted to a fulcrum hole 8B of the center lever8. The center lever 8 is formed such that a line connecting the fulcrumhole 8B and the first supporting portion 8A forms an angle of about 90°with a line connecting the fulcrum hole 8B and the second supportingportion 8C. Further, the connecting point between the right link 9 andthe right lever 10 is positioned at a generally upper-most area withrespect to the center of the right drive shaft 5A. Similarly, theconnecting point between the left link 11 and the left lever 12 ispositioned at a generally upper-most area with respect to the center ofthe left drive shaft SB. Therefore, these connecting points aregenerally horizontally moved (swung) when the swirl control valves 3A to3F are operated by the linkage device 20.

In the first embodiment, the right link 9 corresponds to a firstextending member of the present invention, and the left link 11corresponds to a second extending member of the present invention.

The right link 9 is rotatably connected to a right lever 10 fixedlyconnected to the right drive shaft 5A penetrating the right intakepassages 3A, 3B, 3C, 3D, 3E and 3F. The left link 11 is rotatablyconnected to a left lever 12 fixedly connected to the left drive shaft5B penetrating the left intake passages 3G, 3H, 3I, 3J, 3K and 3L. Moreparticularly, a supporting portion 10A of the right lever 10 isrotatably inserted to a first connecting hole 9A of the right link 9,and a supporting portion 12A of the left lever 12 is rotatably insertedto a first connecting hole 11A of the left link 11. The connectionbetween the right link 9 and the drive shaft 5A has predetermined playwhich is produced by loosely forming the first connecting hole 9A of theright link 9 with respect to the supporting portion 10A. Similarly, Theconnection between the left link 11 and the drive shaft 5B haspredetermined play which is produced by loosely forming the firstconnecting hole 11A of the left link 11 with respect to the supportingportion 12A of the left lever 12. Further, the connection between theright link 9 and the center lever 8 has predetermined play which isproduced by loosely forming a second connecting hole 9B of the rightlink 9 with respect to the second supporting portion 8C. Similarly, theconnection between the left link 11 and the center lever 8 haspredetermined play which is produced by loosely forming a secondconnecting hole 11B of the left link 11 with respect to the secondsupporting portion 8C. It is of course that such plays may be formedonly between the center lever 8 and the right and left links 9 and 11 orbetween the drive shafts 5A and 5B and the right and left links 9 and11.

The manner of operation of the linkage device 20 and the advantagesgained thereby will be discussed hereinafter with reference to FIGS. 4Ato 4C.

As shown in FIGS. 4A to 4C, when the engine operating conditionincluding a load condition, an engine rotation speed, a watertemperature of the engine, and an engine combustion condition is changedfrom a full close state wherein one of two intake passages by eachcylinder is fully closed by a swirl control valve, the negative pressureapplied to a diaphragm chamber 6 a of the actuator 6 is changedaccording to the drive signal from a control unit (not shown). The drivesignal is changed according to the engine operating condition. Accordingto the change of the negative pressure, the rod 7 connected to adiaphragm of the diaphragm chamber 6A is upwardly moved from thecondition of FIG. 4C to the condition of FIG. 4B and the condition ofFIG. 4A.

The center lever 8 is rotated clockwise around the supporting shaft 8Daccording to the upward movement of the rod 7 as viewed on a front sideof each of FIGS. 4A to 4C. The right link 9 connected to the centerlever 8 is moved in the left hand side as shown in FIG. 4B according tothe clockwise rotation of the center lever 8. Therefore, the drive shaft5A is rotated in the anticlockwise direction by the right link 9 rotatedby the right lever 10.

On the other hand, the left link 11 connected to the center lever 8 issimilarly moved in the left hand side according to the clockwiserotation of the center lever 8 as shown in FIG. 4B. Therefore, thedriver shaft 5B is rotated in the anticlockwise direction by the leftlever 12 rotated by the left rink 11. With these anticlockwise rotationsof the right and left drive shafts 5A and 5B, the swirl control valves4A, 4B and 4C set in the intake passages 3B, 3D and 3F for the rightbank 100R and the swirl control valves 4D, 4E and 4F set in the intakepassages 3G, 3I and 3K for the left bank 100L are rotated in the samedirection and are set in an intermediate open state as shown in FIG. 4Bfrom the full close state of FIG. 4C.

When the rod 7 is further moved upward and moved at an uppermost pointas shown in FIG. 4A, the center lever 8 is further rotated in theclockwise direction from the intermediate open state to the full openstate shown in FIG. 4A so as to move the second supporting portion 8C toa left-most position. The right link 9 connected to the center lever 8through the second supporting portion 8C is moved at the left-mostposition as shown in FIG. 4A. Therefore, the right drive shaft 5A isrotated in the anticlockwise direction and put in a maximum rotatedstate. On the other hand, the left link 11 connected to the center lever8 through the second supporting portion 8C is moved at the left-mostposition as shown in FIG. 4A. Therefore, the left drive shaft 5B isrotated in the anticlockwise direction and put in a maximum rotatedstate. With these further anticlockwise rotations of the right and leftdrive shafts 5A and 5B, the right swirl control valves 4A, 4B and 4C andthe left swirl control valves 4D, 4E and 4F are rotated in the samedirection and are set in the full open state as shown in FIG. 4A.

By setting the swirl control valves 4A to 4F in the full open state, theintake air is supplied to each cylinder #1, #2, #3, #4, #5, #6 throughboth of the two intake passages 3A and 3B, 3C and 3D, 3E and 3F, 3G and3H, 3I and 3J, 3K and 3L. Therefore, the flow speed of the intake air isdecreased and the flow of the intake air from the one intake passage 3A(3C, 3E, 3G, 3I, 3L) collides with the other flow of the intake air fromthe other intake passage 3B (3D, 3F, 3H, 3J, 3L) in the combustionchamber so as to suppress the generation of the swirl in each combustionchamber. This swirl suppressing control enables the combustion in eachcombustion chamber under the high-speed range to be optimized.

That is, by controlling the openings of the swirl control valves 4A to4F according to the engine operating condition and the combustioncondition in the engine 100, an optimized control of the swirl isexecuted according to the engine operating condition and the combustioncondition in the engine 100. This improves the combustion in thecombustion chamber of each cylinder #1, #2, #3, #4, #5, #6 of the engine100.

Since the first embodiment according to the present invention isarranged to drive both of the right and left drive shafts 5A and 5B bymeans of one actuator 6 through the linkage device 20 and to dispose theactuator 6 at a portion between the drive shafts 5A and 5B, it ispossible to arrange the actuator 6 and the linkage device 20 within apredetermined space between the intake passages 3A to 3L and the enginemain body. This enables the swirl control system to produce small insize.

Further, since the first embodiment according to the present inventionis arranged to locate the second supporting portion 8C between theactuator 6 and the fulcrum hole 8B of the center lever 8, the verticaldimension of the linkage device 20 is suppressed small. Accordingly, thedegree of the freedom as to the design of the swirl control system islargely improved and therefore it is possible to improve the swirlcontrol system in weight and in cost.

Additionally, since the first embodiment according to the presentinvention is arranged to rotate the drive shafts 5A and 5B through thecenter lever 8, it is easy to change the moving (rotation) amount of theswirl control valves by changing a lever ratio of the center lever 8,which ratio is a ratio between a distance between the supporting portion7A and the fulcrum portion 8B and a distance between the fulcrum portion8B and the second supporting portion 8C, while improving a spaceutility. Therefore, it is possible to simplify the structure of theswirl control system and to decrease the volume of the swirl controlsystem.

Further, with the thus arranged linkage device 20 of the firstembodiment, since the linkage device 20 is arranged to absorb thetorsion of the right and left drive shafts 5A and 5B caused by thetemperature difference between the right and left banks 100R and 100L ofthe engine 100 by means of the play generated by the linkage device 20,the degradation of the drivability by the temperature difference isprevented although the temperature difference tends to be caused betweenthe banks or cylinders by the difference of the radiation performance oneach surface or by unequal cooling through coolant. That is, the linkagedevice 20 according to the present invention is arranged such that theright and left links 9 and 11 are rotatably connected to the driveshafts 5A and 5B, respectively, with respective plays. These connectionswith plays function to cancel the unnecessary stress between the partssuch as between the drive shaft and the link. For example, even if thetemperature difference is generated among cylinders in the same bank,the torsion of the drive shaft 5A, 5B is prevented by this arrangementof the linkage device 20.

The conventional arrangement for directly actuating the drive shaft isnot constructed so as to cancel stress applied to the drive shaft whenthe temperature difference is generated between the intake passages suchas 3A and 3B so as to increase the angle therebetween. Therefore, incase of such a conventional arrangement, a forcible stress is applied tothe drive shaft and the like so as to generate gall of the drive shaftsor breakage thereof.

Further, if the swirl control system is arranged such that one of thetwo drive shafts is directly driven by the actuator and the other isdriven through a linkage device as conventionally, it is difficult tosynchronously operate the two drive shafts. That is, since the otherdrive shaft driven through the link device generates a time delay withrespect to the drive shaft directly driven by the actuator due todifference of play of the drive shafts, the difference of the rotatedangles of the respective drive shafts is generated. This generates thedifference between opening degrees of the swirl control valves of therespective banks. Accordingly, the swirls and the combustion in eachcylinder are fluctuated and degraded.

In contrast, the swirl control system employing the linkage device 20according to the present invention suppresses such dispersion and thedegradation. That is, the first embodiment according to the presentinvention is arranged to generally equivalently transfer thereciprocating motion of the rod 7 to the rotations of the right and leftdrive shafts 5A and 5B through the center lever 8, the right and leftlinks 9 and 11 and the right and left levers 10 and 12. This preventsthe right and left drive shafts 5A and 5B from generating theoperational difference therebetween, and therefore the differencebetween the openings of the right swirl control valves 4A, 4B and 4C andthe left swirl control valves 4D, 4E and 4F. Therefore, the swirlcontrol system employing the linkage device 20 according to the presentinvention enables the cancellation of the opening difference between theright and left swirl control valves 4A, 4B, 4C and 4D, 4E, 4F.Consequently, the first embodiment according to the present inventionsuppresses the degradation in the engine drivability.

Furthermore, as shown in FIG. 5, the linkage device 20 according to thepresent invention is arranged so that the second supporting portion 8C,the supporting portion 10A, the supporting portion 12A, the right andleft drive shafts 5A and 5B are not simultaneously located on a straightline such as the line Z of FIG. 5. Therefore, it is possible to preventthe generation of galls of the levers 10 and 12 and links 9 and 11 andabrasion at the supporting portions 8C, 10A and 12A.

That is, if the supporting portions 8C, 10A and 12A and the right andleft drive shafts 5A and 5B are arranged to locate on a straight lineunder the full open state of the swirl control valves 4A to 4F, thelinkage device may not be able to properly operate. More particularly,in such a setting under the full open state, the right link 9 may belocked so as not to be able to be rotated between the second supportingportion 8C and the supporting portion 10A when the center lever 8 isrotated in the anticlockwise direction to close the swirl control valves4A to 4F.

In contrast, according the arrangement of the linkage device 20 it ispossible to correctly apply rotational motion to the right and leftdrive shafts 5A and 5B while preventing the gall of the levers and thelinks and the abrasion of the supporting portions. The above-mentionedadvantages are ensured regardless the dimensional difference between theright and left links 9 and 11.

Further, it is preferable that the linkage device 20 according to thepresent invention is applied to an intake system including the intakepassages 3A to 3L shown in FIG. 6. That is, when the right intakepassages 3A to 3F connected to the right bank 100R of the engine 100have bent portions as shown in FIG. 6, the main flow of the intake airin the right intake passages 3A to 3F flows along an outer curvedportion in the intake passages 3A to 3F as indicated by white arrows inFIG. 6. The main flow of the intake air in the left intake passages 3Gto 3L also flows along outer curved portion in the left intake passages3G to 3L as indicated by white arrows in FIG. 6. As shown in FIG. 6, themain flow of the intake air in each of intake passages 3B, 3D, 3F, 3G,3I and 3K provided with each of the swirl control valves 4A to 4Freaches the left side portion of each intake passages. The swirl controlvalves 4A to 4F are opened by rotating them in the anticlockwiserotation and are arranged such that the left side portion of each of theswirl control valves 4A to 4F is located at a down stream side ascompared with the right side portion of each of them. That is, when theswirl control valves 4A to 4F are opened, the main flow of the intakeair of the intake passages 3B, 3D, 3F, 3G, 3I and 3K smoothly reachesthe respective cylinder #1, #2, #3, #4, #5 and #6 through the swirlcontrol valves 4A to 4F.

Consequently, the linkage device 20 applied to the intake passages shownin FIG. 6 function to smoothly flow intake air to both of the right andleft banks 100R and 100L of the engine 100 while suppressing thepressure loss of the intake passages. Therefore, the flow of the intakeair including the swirl is stabilized, and the combustion in eachcylinder is also stabilized.

Referring to FIGS. 7 to 8C, there is shown a second embodiment of alinkage device 30 of a swirl control valve system of the V-typesix-cylinder internal combustion engine, in accordance with the presentinvention.

Basically the construction of the second embodiment is the same as thatof the first embodiment shown in FIGS. 1 and 2 except that the linkagedevice 20 is replaced with the linkage device 30 shown in FIG. 7. Moreparticularly, the linkage device 30 of the second embodiment comprisesright and left links 31 and 32 and right and left levers 33 and 34 whichare different from the right and left links 9 and 11 and the right andleft levers 10 and 12 of the linkage device 20 of the first embodiment.The other elements and parts of the second embodiment are the same asthose of the first embodiment. Therefore, they are designated by thesame reference numeral of the first embodiment, the explanation thereofis basically omitted herein.

As shown in FIG. 7, the rod 7 reciprocated by the actuator 6 isconnected to the center lever 8 as is the same in the first embodiment.The center lever 8 is rotatably supported to the engine main body in amanner that the fulcrum hole 8B of the center lever 8 is rotatablyengaged with a supporting shaft 100A of the engine main body.

Further, the center lever 8 is rotatably connected with the right link31. The right link 31 is formed into L-shape and extends from the secondsupporting portion 8C to a supporting portion 33A of the right lever 33.The right link 31 has a first connecting hole 31A rotatably connected tothe right lever supporting portion 33A and a second connecting hole 31Brotatably connected to the second supporting portion 8C. Therefore, thedrive shaft 5A is rotated in the clockwise direction on FIG. 7 when theright link 31 is moved in the left hand side in Figure. The left link 32extends from the second supporting portion 8C to a supporting portion34A of the left lever 34. The left link 32 has a first connecting hole32A rotatably connected to the left lever supporting portion 34A and asecond connecting hole 32B rotatably connected to the second supportingportion 8C. Therefore, the drive shaft 5A is rotated in theanticlockwise direction on FIG. 7 when the right link 31 is moved in theleft hand side in Figure.

The right link 31 corresponds to a first extending member of the presentinvention, and the left link 32 corresponds to a second extending memberof the present invention.

The right link 31 is rotatably connected to a right lever 33 fixedlyconnected to the right drive shaft 5A disposed in the right bank 100R.The left link 32 is rotatably connected to a left lever 34 fixedlyconnected to the left drive shaft 5B disposed in the left bank 100L.More particularly, the supporting portion 33A of the right lever 33 isrotatably inserted to the first connecting hole 31A of the right link31, and the supporting portion 34A of the left lever 34 is rotatablyinserted to the first connecting hole 32A of the left link 32. Theconnection between the right link 31 and the drive shaft 5A haspredetermined play which is produced by loosely forming the firstconnecting hole 31A of the right link 31 with respect to the supportingportion 33A of the right lever 33. Similarly, The connection between theleft link 32 and the drive shaft 5B has predetermined play which isproduced by loosely forming the first connecting hole 32A of the leftlink 32 with respect to the supporting portion 34A of the left lever 34.Further, the connection between the right link 31 and the center lever 8has predetermined play which is produced by loosely forming the secondconnecting hole 31B of the right link 31 with respect to the secondsupporting portion 8C. Similarly, the connection between the left link32 and the center lever 8 has predetermined play which is produced byloosely forming the second connecting hole 32B of the left link 32 withrespect to the second supporting portion 8C. It is of course that suchplays may be formed only between the center lever 8 and the right andleft links 31 and 32 or between the drive shafts 5A and 5B and the rightand left links 31 and 32.

The manner of operation of the linkage device 30 of the secondembodiment and the advantages gained thereby will be discussedhereinafter with reference to FIGS. 8A to 8C.

That is, as shown in FIGS. 8A to 8C, when the engine operating conditionincluding conditions of a load, an engine rotation speed, a watertemperature of the engine, and an engine combustion is changed from afull close condition wherein one of two intake passages by each cylinderis fully closed, the negative pressure being applied to a diaphragmchamber 6 a of the actuator 6 is changed according to the drive signalfrom the control unit. The drive signal is changed according to theengine operating condition. The rod 7 connected to a diaphragm of thediaphragm chamber of the actuator 6 is upwardly moved from the conditionof FIG. 8C to the condition of FIG. 8B.

The center lever 8 is rotated clockwise around the supporting shaft 8Daccording to the upward movement of the rod 7 as viewed on the front ofFIGS. 8A to 8C. The right link 31 connected to the center lever 8 ismoved in the left hand side as shown in FIG. 8B according to theclockwise rotation of the center lever 8. Therefore, the drive shaft 5Ais rotated in the clockwise direction by the right lever 33 through thefirst supporting portion 31A.

On the other hand, the left link 32 connected to the center lever 8 issimilarly moved in the left hand side as shown in FIG. 8B according tothe clockwise rotation of the center lever 8. Therefore, the drivershaft 5B is rotated in the anticlockwise direction by the left lever 34through the first supporting portion 32A. With the clockwise rotation ofthe drive shaft 5A and the anticlockwise rotation of the drive shaft 5B,the swirl control valves 4A, 4B and 4C set in the intake passages 3B, 3Dand 3F for the right bank 100R and the swirl control valves 4D, 4E and4F set in the intake passages 3G, 3I and 3K for the left bank 100L arerotated in the opposite direction and are set in an intermediate openstate as shown in FIG. 8B.

When the rod 7 is further moved upward and moved at an uppermost point,the center lever 8 is further rotated in the clockwise direction fromthe intermediate open state to the full open state shown in FIG. 8A soas to move the second supporting portion 8C to a left-most position. Theright link 31 connected to the center lever 8 through the secondsupporting portion 8C is moved at the left-most position as shown inFIG. 8A. Therefore, the right drive shaft 5A is rotated in the clockwisedirection to a maximum rotated state. On the other hand, the left link32 connected to the center lever 8 through the second supporting portion8C is moved at the left-most position as shown in FIG. 8A. Therefore,the left drive shaft 5B is rotated in the anticlockwise direction at amaximum rotated state. With these further rotations of the right andleft drive shafts 5A and 5B, the right swirl control valves 4A, 4B and4C and the left swirl control valves 4D, 4E and 4F are rotated in theopposite direction and are set in the full open state as shown in FIG.8A.

By setting the swirl control valves 4A to 4F in the full open state, theintake air is supplied to each cylinder #1, #2, #3, #4, #5, #6 throughboth of the two intake passages 3A and 3B, 3C and 3D, 3E and 3F, 3G and3H, 3I and 3J, 3K and 3L. Therefore, the flow speed of the intake air isdecreased and the flow of the intake air from the one intake passage 3A(3C, 3E, 3G, 3I, 3L) collides with the another flow of the intake airfrom the other intake passage 3B (3D, 3F, 3H, 3J, 3L) in the combustionchamber so as to suppress the generation of the swirl in each combustionchamber. This swirl suppressing control enables the combustion in eachcombustion chamber under the high-speed range to be optimized.

That is, by controlling the openings of the swirl control valves 4A to4F according to the engine operating condition and the combustioncondition in the engine 100, an optimized control of the swirl isexecuted according to the engine operating condition and the combustioncondition in the engine 100. This improves the combustion in thecombustion chamber of each cylinder #1, #2, #3, #4, #5, #6 of the engine100.

Since the second embodiment according to the present invention isarranged to drive both of the right and left drive shafts 5A and 5B bymeans of one actuator 6 through the linkage device 30 and to dispose theactuator 6 at a portion between the drive shafts 5A and 5B as is thesame as the first embodiment, it is possible to arrange the actuator 6and the linkage device 30 within a predetermined portion between theintake passages 3A to 3L and the engine main body. This enables theswirl control system to produce small in size.

Further, since the second embodiment according to the present inventionis arranged to locate the second supporting portion 8C between theactuator 6 and the fulcrum hole 8B of the center lever 8, the verticaldimension of the linkage device 30 is suppressed small. Accordingly, thedegree of the freedom as to the design of the swirl control system islargely improved and therefore it is possible to improve the swirlcontrol system in weight and in cost.

Additionally, since the second embodiment according to the presentinvention is arranged to rotate the drive shafts 5A and 5B through thecenter lever 8, it is easy to change the moving (rotation) amount of theswirl control valves by changing a lever ratio of the center lever 8,which ratio is a ratio between a distance between the supporting portion7A and the fulcrum hole 8B and a distance between the fulcrum hole 8Band the second supporting portion 8C, while improving space utility.Therefore, it is possible to simplify the structure of the swirl controlsystem and to decrease the volume of the swirl control system.

Further, with the thus arranged linkage device 30 of the secondembodiment, since the linkage device 30 is arranged to absorb thetorsion of the right and left drive shafts 5A and 5B caused by thetemperature difference between the right and left banks 100R and 100L ofthe engine 100 by means of the play generated by the linkage device 30,the degradation of the drivability by the temperature difference isprevented although the temperature difference tends to be caused betweenthe banks or cylinders by the difference of the radiation performance oneach surface or by unequal cooling through coolant. That is, the linkagedevice 30 according to the present invention is arranged such that theright and left links 31 and 32 are rotatably connected through the rightand left levers 33 and 34 to the drive shafts 5A and 5B, respectively,with respective plays. These connections with plays function to cancelthe unnecessary stress between the parts such as between the drive shaftand the link. For example, even if the temperature difference isgenerated among cylinders in the same bank, the torsion of the driveshaft 5A, 5B is prevented by this arrangement of the linkage device 30.

Since the conventional arrangement for directly actuating the driveshaft is not constructed so as to cancel stress applied to the driveshaft when the temperature difference is generated between the intakepassages such as 3A and 3B so as to increase the angle therebetween, aforcible stress is applied to the drive shaft and the like so as togenerate gall of the drive shafts or breakage thereof. In contrast, theswirl control system employing the linkage device 30 according to thepresent invention suppresses such dispersion and the degradation.

Furthermore, as shown in FIG. 7, the linkage device 30 according to thepresent invention is arranged so that the second supporting portion 8C,the supporting portion 33A, the supporting portion 34A, the right andleft drive shafts 5A and 5B are not simultaneously positioned on astraight line. Therefore, the linkage device 30 securely appliesrotational moment to the right and left drive shaft through the rightand left links 31 and 32 and the right and left levers 33 and 34 and toprevent the generation of galls of the levers 33 and 34 and links 31 and32 and abrasion at the supporting portions 8C, 32A and 34A.

It will be understood that the above-mentioned advantages are ensuredregardless the lengths of the right and left links 31 and 32.

Further, it will be understood that return springs for applyingreturning-force may be installed to the drive shafts 5A and 5B, in orderto securely and quickly rotate the right and left drive shafts 5A and 5Bfrom predetermined rotated positions to the initial position.

Although the preferred embodiments according to the present inventionhave been shown and described so as to be applied to a V-typesix-cylinder internal combustion engine, it will be understood that thepresent invention is not limited to the engine of this type and may beapplied to other engines such as a horizontal opposed type engine orother multi-bank type engine.

While the preferred embodiments according to the present invention havebeen shown and described such that the linkage devices 20 and 30 areapplied to swirl control valve control system, it will be understoodthat the linkage devices 20 and 30 according to the present inventionmay be applied to a system wherein two rotation shafts are rotated byone reciprocate-type actuator, such as a throttle value operating systemor EGR valve operating system.

What is claimed is:
 1. A linkage device of an internal combustion enginecomprising: a reciprocating member; a connecting member comprising firstand second supporting portions, the first supporting portion beingrotatably connected to said reciprocating member; a supporting memberrotatably supporting said connecting member so that the first and secondsupporting portions are swingable around said supporting member; firstand second extending members rotatably connected to the secondsupporting portion of said connecting member, said second extendingmember extending from the second supporting portion toward an oppositedirection of an extending direction of said first extending member;first and second lever members rotatably connected to said first andsecond extending members, respectively; and first and second rotationshafts fixed to said first and second lever members, respectively, saidfirst and second rotation shafts being synchronously rotated when saidreciprocating member is reciprocated, wherein the engine employing thelinkage device is a V-type engine comprising first and second banks, andwherein first swirl control valves are fixed to said first rotationshaft and second swirl control valves are fixed to said second rotationshaft.
 2. A linkage device as claimed in claim 1, wherein the secondsupporting portion of said connecting member is located between saidsupporting member and a drive source for reciprocating saidreciprocating member.
 3. A linkage device as claimed in claim 1, whereinsaid first extending member is rotatably connected to said first leverwith predetermined play, and said second extending member is rotatablyconnected to said second lever with predetermined play.
 4. A linkagedevice as claimed in claim 1, wherein said first and second extendingmembers are rotatably connected to said connecting member withpredetermined plays.
 5. A linkage device as claimed in claim 1, whereinsaid first and second rotation shafts are rotated in the same directionaccording to reciprocating motion of said reciprocating member.
 6. Alinkage device as claimed in claim 1, wherein a first connecting pointbetween said first extending member and said first lever, a secondconnecting point between said second extending member and said secondlever and the second supporting portion are arranged so as not to bealigned on a straight line.
 7. A linkage device as claimed in claim 1,wherein said connecting member is a bell crank.
 8. A linkage device asclaimed in claim 1, wherein said connecting member is arranged such thata line connecting the first supporting portion and a portion supportedto said supporting member forms an angle of about 90° with a lineconnecting the second supporting portion and the portion supported tosaid supporting member.
 9. A linkage device as claimed in claim 1,wherein a connecting point between said first link and said first leveris positioned at a generally upper-most area with respect to the centerof said first rotation shaft, and a connecting point between said secondlink and said second lever is positioned at a generally upper-most areawith respect to a center of the second rotation shaft.
 10. A linkagedevice as claimed in claim 1, wherein these connecting points aregenerally horizontally swung when said first and second rotation shaftsare rotated.
 11. A linkage device as claimed in claim 1, wherein saidfirst swirl control valves are disposed in first intake passages andsaid second swirl control valves are disposed in second intake passages.12. A linkage device of a V-type internal combustion engine comprising:a reciprocating rod; a center lever having first and second supportingportions and a fulcrum portion, the first supporting portion beingrotatably connected with said reciprocating rod, the fulcrum portionbeing rotatably supported to a portion of the engine so that the firstand second supporting portions swing around the fulcrum portion; a firstlink having input and output portions, the first link input portionbeing rotatably connected to the second supporting portion of saidcenter lever; a second link having input and output portions, the secondlink input portion being rotatably connected to the second supportingportion of said center lever; a first drive shaft rotatably disposed infirst intake passages connected to a first bank of the V-type engine; asecond drive shaft rotatably disposed in second intake passagesconnected to a second bank of the V-type engine; a first lever fixed tosaid first drive shaft, said first lever having a connecting portionrotatably connected to the first link output portion, the first leverconnecting being swung on said first drive shaft according toreciprocating motion of said reciprocating rod so that said drive shaftis rotated; and a second lever fixed to said second drive shaft, saidsecond lever having a connecting portion rotatably connected to thesecond link output portion, said first lever being swung on said seconddrive shaft according to reciprocating motion of said reciprocating rodso that said second drive shaft is rotated.
 13. A linkage device of aninternal combustion engine comprising: a reciprocating member; aconnecting member comprising first and second supporting portions, thefirst supporting portion being rotatably connected to said reciprocatingmember; a supporting member rotatably supporting said connecting memberso that the first and second supporting portions are swingable aroundsaid supporting member; first and second extending members rotatablyconnected to the second supporting portion of said connecting member,said second extending member extending from the second supportingportion toward an opposite direction of an extending direction of saidfirst extending member; first and second lever members rotatablyconnected to said first and second extending members, respectively; andfirst and second rotation shafts fixed to said first and second levermembers, respectively, said first and second rotation shafts beingsynchronously rotated in opposite directions according to areciprocating motion of said reciprocating member when saidreciprocating member is reciprocated.